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Monogamy, the mating system of only having one partner at a time, is generally rare within the animal kingdom and largely restricted to birds. Social monogamy is applied to pairs that remain together throughout their lives, but do not necessarily mate exclusively with one partner. Approximately 90% of birds are described as socially monogamous for although these pairs will remain with the same partner for life, many will seek to mate with other partners. Genetic monogamy, which refers to exclusive mating between two pairs, is rare within vertebrates. For example, only 25% of socially monogamous bird species are actually genetically monogamous. The evolution of genetic monogamy has been of interest to biologists for many decades and it is thought that biparental care, where both parents look after the offspring, has been an important factor in driving the evolution of monogamy. In species where biparental care is crucial for the offspring survival, working together results in greater survival of the young and greater reproductive output.

Parental care is generally rare within the amphibians and paternal care is considered to be the first form of parental care to have evolved. This is in contrast to birds and mammals, where maternal care appears to have evolved first. Within the amphibians parental care is often associated with tropical terrestrial species, particularly poison dart frogs belonging to the genus Ranitomeya. After females have laid their small clutches of eggs the males often carry the eggs to phytotelmata (pools of water in the axils of tree-dwelling plants) and exhibit egg-guarding. Biparental care has subsequently evolved where by females may lay non-fertile (or trophic) eggs in these small bodies of water to feed developing larvae. Known as trophic feeding, this form of maternal care has been reported from a range of terrestrial breeding tropical frog species and within the Ranitomeya, is associated with larvae developing in very nutrient poor, small bodies of water.

Figure 1. Mimic poison frog (Ranitomeya imitator). Both males and females exhibit parental care, which has driven the evolution of monogamy in this species.

Recent research has shown that where biparental care has evolved in amphibian species, this has also resulted in the evolution of genetic monogamy. Prior to 2010, social and genetic monogamy had not been recorded in any species of amphibian. However, research by Brown et al. (2010) documented that social and genetic monogamy occurs in the mimic poison frog (Ranitomeya imitator) (Figure 1). This species occurs in north-central Amazonian Peru, in the regions of Loreto and San Martín and occurs in rainforest habitats between 200 and 1,200 m (Figure 2). Following courtship, the female mimic poison frog lays arboreal clutches of 1–3 eggs on understorey vegetation. The male guards the egg clutches and transports individual tadpoles on their backs to small phytotelmata. The female then lays trophic eggs into the water to provide food for the developing larvae. In an experimental study, Brown et al. (2010) found that 11 out of 12 pairs investigated showed genetic as well as social monogamy by the use of molecular markers. However, the closely related R. variabilis shows no monogamy and is highly promiscuous. In this species the male provides parental care but the female does not provide trophic eggs. Pairs preferred larger pools for tadpole deposition which contain higher levels of nutrients so additional trophic feeding by the female is less required (Brown et al., 2008). It appears that small pool size with low nutrient levels is crucial in driving the evolution of biparentral care and monogamy in species of poison dart frogs. Brown et al. (2010) experimentally confirmed the importance of trophic feeding by showing that tadpoles denied trophic eggs had lower growth rates than controls. Further experiments by Tumulty et al. (2016) demonstrated a significant reduction in reproductive success when males were removed after tadpole deposition, establishing the importance of male care for tadpole growth and survival throughout development. Therefore, because R. imitator breeds in small, low-nutrient waterbodies, both males and females are required to provide parental care. This requirement for active parental care from both the male and female appears to have driven the evolution of genetic monogamy and stable pair bonds in this species.

Figure 2. Populations of the mimic poison frog (Ranitomeya imitator) occur within the Regional Conservation Area of Cordillera Escalera, Peru.

Many studies have shown that there are many advantages to biparental care but the high occurrence of extra pair matings, particularly in birds, indicates that there are many genetic advantages to having more than one mate. Therefore, why is the poison mimic frog so exclusively monogamous? The answer seems to lie in the importance of both male and female parental care in the pair bond. Experimental work on species where both partners are crucial for the survival of the young show that monogamy is strong, whereas in species where one partner is not obligatory, the level of monogamy is often weaker. This correlation suggests that genetic monogamy may be favoured when both male and female care is required for offspring survival. Results by Tumulty et al. (2016) indicate this to be the case in R. imitator, which has low rates (8.3%) of extra pair matings.

Overall, the biparental care hypothesis for promoting evolution of monogamy is gaining support from a variety of taxonomic groups and results from recent studies indicate that R. imitator shows a highly stable and cooperative long-term association between male and female and both care mutually for their offspring. The selection for long-term biparental care, as required by the demands of small, low nutrient pool size has driven the evolution of social and genetic monogamy in R. imitator.

Volunteers from a local company helped contribute to the work of Froglife in looking after Orton Pits, highlighting the value of connecting people with wildlife.

Employees from BGL Group volunteered their time to monitor water quality and build new homes for wildlife at one of the UK’s most important pond sites.

Orton Pits, Peterborough, is owned by O&H and mangaged by the charity Froglife. This site is also part of the Freshwater Habitat Trust’s Flagship ponds project – one of 70 sites across the country that are home to our rarest pond plants and animals. Froglife is working with the Freshwater Habitats Trust and local communities to enhance Flagship Ponds and their wildlife to have a safe future. When companies like BGL join the team, it bodes well.

Without help from Froglife and local people, sites like those at Orton Pits will likely suffer the same fate as most other ponds: pollution, neglect or mismanagement, and the loss of the plants and animals that make them special.

Pete Case, Freshwater Habitat Trust’s Regional Officer, said: “Volunteers play an incredibly important role in helping to care for Flagship Pond sites. Everything from monitoring water quality to undertaking hands-on practical management work relies on their support, so having the enthusiastic staff from BGL to help us for the day was a real bonus. It was a pleasure to show the team around Orton Pits which is one of the best and most interesting freshwater sites in England, we are looking forward to working with them again in the future”.

Staff at BGL are encouraged to spend one work day a year volunteering in the local community. Earlier this month, eight volunteers from BGL’s head office in Peterborough enjoyed building log piles to give shelter to the Great Crested Newts that the site is best known for. The volunteers then spent the afternoon measuring pollution levels in some the site’s 320 ponds. The water testing is vital for spotting pollution that could threaten the many other special plants and animals that have made Orton Pits their home.

Louise Powell, Senior Business Analyst at BGL, said “We were delighted to spend our volunteering day at Orton Pits – we were thrilled to see so many creatures and birds, including a few slow worms, a kingfisher and a deer. We came away with a real understanding of the value of the Reserve, what effects pollutants can have on our waterways and the importance in protecting these areas. We look forward to helping again in the future.”

Laurence Jarvis, Head of Conservation at Froglife, said “We were very pleased with the work which staff from BGL carried out at Orton Pit. The wildlife homes will be valuable for a range of species including Great Crested Newts, Common Lizards and Adders. This volunteer input really contributes to the continued conservation of species and habitats on the reserve”.

Freshwater Habitats Trust’s Flagship Pond project is working with partners such as Froglife and local communities to protect 70 sites across England and Wales, with Heritage Lottery Fund support.

Today researchers from the University of Cambridge announce a partnership with nature conservation groups, aimed at getting the best science to busy on-the-ground conservationists.

‘Evidence-based conservation’ and ‘evidence-based policy’ have become buzzwords in the last decade, with a 2004 paper entitled ‘The need for evidence-based conservation’ cited over 1000 times. But within nature conservation, studies have shown that many organisations do not have access to scientific papers, and are working in the dark.

The Conservation Evidence Project (ConservationEvidence.com), set up by Professor Bill Sutherland at the University of Cambridge, summarises the scientific evidence on different conservation interventions that people have done all around the world. Their work so far includes the conservation of birds, bees, frogs and forests; they aim to cover all species and habitats in the next few years. Crucially, this information is made available for free, so anyone can read it and see what has worked – and what hasn’t. However, some conservation groups are still not using the available science, meaning they may not be as effective as they could be in conserving nature.

Several leading conservation organisations interested in the Conservation Evidence approach have decided to make it a key part of their decision-making and become Evidence Champions. The Vincent Wildlife Trust, Froglife, the People’s Trust for Endangered Species and Oryx have all pledged to check the scientific evidence on ConservationEvidence.com every time they make a conservation decision. They are also keen to embrace the Conservation Evidence Project’s culture of experimental conservation by testing many of the actions they undertake – and researchers from the University of Cambridge will help them to design scientific studies to see how well their projects have worked, and publish the results so others can learn from their work.

Dr Henry Schofield, Conservation Director of The Vincent Wildlife Trust, was instrumental in developing his organisation’s partnership with the Cambridge scientists. ‘We have been leaders in innovations to protect British and Irish mammals, especially the rare horseshoe bats. We have designed bespoke bat houses, predator-proof bat entrances and enhanced major hibernation sites. With the help of the University of Cambridge staff we can measure the impact we have had, and share the results with other conservationists.’

Kathy Wormald, Chief Executive Officer of Froglife, has already arranged for the Conservation Evidence staff from Cambridge to train her team in using the Conservation Evidence website and designing ways to test the impact of their conservation projects. ‘We are committed to delivering the best possible conservation outcomes, and a better understanding of the impacts of our projects will help us to do this. We have seen how much useful information there is on amphibian conservation on the Conservation Evidence website; but the website has also highlighted areas where there is still a lot to learn. We have the expertise to fill those knowledge gaps, and aim to start doing so this year.’

Nida Al-Fulaij, Grants Manager at People’s Trust for Endangered Species, is deploying her considerable influence as a funder to spread the evidence-based conservation message. ‘We’ll be asking all our grantees to check the evidence for their proposed projects on the Conservation Evidence website. This will help us to fund the projects with the highest chance of success. We will also be encouraging the conservationists that we fund to test their work and publish it in Conservation Evidence’s journal, so we can be constantly improving conservation science.’

Martin Fisher, the editor of Oryx (The International Journal of Conservation Fauna & Flora), feels that his journal’s decision to ask contributors to discuss the evidence on ConservationEvidence.com will improve the standard of discussion in papers and even affect how projects are planned. ‘We know that humans have a tendency to cherry pick and discuss the existing literature that supports their views – if they check the totality of evidence collected on the website, this can be avoided. We hope that as authors experience checking the existing evidence they will also start to check it before undertaking conservation interventions – and this may lead to the avoidance of approaches already shown to be unsuccessful.’

For conservation, developing a rigorous, evidence-based culture similar to that seen in medicine could be a game changer. In medicine, careful tests of treatments showed some routinely used methods were ineffective, or even harmful; and this helped develop the effective medical care we enjoy today. Professor Bill Sutherland envisages the same approach revolutionising nature conservation, a typically underfunded discipline.

“Routinely checking the evidence before starting a project is clearly the conservation model of the future. We think conservation can be as science led, experimental and innovative as medicine; we just apply the lessons learned from healing people, to healing the planet”.

Late spring and early summer is the time of year that juvenile temperate breeding amphibians undergo post-metamorphic dispersal. Such movements are defined as “unidirectional movements from natal sites which ultimately result in individuals finding new breeding sites” (Semlitsch, 2008). Newly emerged metamorphs are often extremely small and vulnerable to external environmental factors. For example common toad (Bufo bufo) metamorphs may only be 10 mm in length and therefore have less locomotor capacity and are subject to more rapid water loss than adults. In addition, due to their tiny size and very active behaviour during periods of light rain, rates of exposure may be quite high relative to their body mass. This life stage may represent the period when amphibians are most at risk to harmful effects from exposure to pesticides and other chemicals. Due to their small size and vulnerability, in the first year juvenile amphibians are most likely to be limited to areas adjacent to the breeding pond where they feed, continue to grow, and find over-wintering sites. It is not until later in the season or after the second or third year, when juveniles are larger, that they move greater distances and seek alternative breeding sites. Therefore finding suitable resting habitats where they can seek protection is crucial in the early weeks of life.

Since metamorphs have no prior knowledge of the habitats surrounding ponds, it might be expected that individuals disperse randomly into terrestrial habitats. In a review of the dispersal of European and North American amphibians, Semlitsch (2008) concluded that there is little evidence to suggest that juvenile amphibians have specialized abilities to find new or alternative breeding sites, such as a water-finding ability or by using sounds of breeding choruses of anurans, which might indicate that juveniles exhibit target-oriented dispersal. In his review, Semlitsch (2008) suggested that newly metamorphosed individuals disperse from natal ponds in a random pattern relative to landscape features beyond the pond perimeter and subsequently find new or non-natal breeding ponds primarily by chance. For example, results from a study on Red-Spotted Salamanders (Notophthaltnus viridescens) from Missouri, USA indicated that although adults leaving breeding ponds oriented with respect to forested habitat, metamorphs tended to disperse from the pond in all directions, with 42% emigrating towards the forest and 58% emigrating towards the grassland. Both adults and juveniles of this species are unable to cross grassland, with forest habitats favoured. Those metamorphs emigrating towards grassland experienced higher mortality.

However, a growing number of field studies have found that metamorphs of some species do exhibit targeted, non-random movements towards favourable habitats, despite having no prior knowledge of the surrounding habitats. Recent research on Australian Green and Golden Bell frogs (Litoria aurea) suggests that newly emerged metamorphs preferred the habitat closest to the presence of other metamorphs of the same species (Figure 1). The advantages of using conspecific cues to determine dispersal direction is to reduce search costs by spending less time searching in non-suitable habitat and seeking out suitable habitats more effectively.

A field study on Great Crested Newts (Triturus cristatus) and Smooth Newts (Lissotriton vulgaris) indicates that non-random dispersal of both adults and juveniles may occur when leaving ponds. Juveniles of both T. cristatus and L. vulgaris migrated faster and to a much greater distance from the pond than their conspecific adults (Figure 2). A high percentage of freshly metamorphosed juveniles of both species showed the same clear preferences for a woodland habitat like the adults. This is surprising, as the juveniles lack the familiarity with the quality of their terrestrial surroundings. The results therefore indicate that juvenile newts possess a method for detecting and orienting towards favourable habitats that probably become modified later in life by individual experience. In addition, Hayward (2010) demonstrated that great crested newts were able to identify chemical cues left on the substrate and follow the route taken by previous newts. This suggests that metamorphs may follow adults to terrestrial and possibly hibernation sites.

A knowledge of the core terrestrial habitat requirements of a particular amphibian species is required for local protection of populations. Understanding how and in what directions metamorphs may disperse is important in limiting mortality in a human-dominated landscape. If metamorphs of a particular species have the capacity to orient towards favoured woodland habitats, this may avoid unnecessary mortality. However, if individuals disperse randomly from ponds, in a landscape where suitable terrestrial habitat is limited, high rates of mortality may occur if individuals orient towards roads, barriers or other human hazards. Therefore a knowledge of the behavioural tendency of species or stages during dispersal might be critical to directing conservation efforts. However, at present, the phenomenon of dispersal in amphibians is poorly understood and needs more attention. In particular, the potential relationship of sex, body size, density-dependence, population size, habitat quality, and land use to dispersal tendency and behaviour needs to be examined.

References

Defra (2010) Use of agricultural areas by amphibians. Research Project Final Report, PS3240. Defra, UK.

From the 17th of July to the 20th, I have been working with Froglife to gain some experience in the world of work. The week was packed with interesting activities that varied from chopping down willow to helping line a pond. These tasks helped to build some key skills within the workplace, such as working well within a team and solving any problems we came across.

Monday morning started with an induction, during which I was introduced to other members of staff at Froglife, given a tour of the Froglife building and informed of safety procedures.

Soon after, I was shown how Froglife’s social media pages are managed. As it’s an account that posts three times a day, the posts are scheduled to be released at specific times.

Followed by this, I visited Castor Hang lands with two members of staff and another work experience student. Our task was to cut down the willow around the pond. This was important because the willow absorbs the pond water.

Once we had finished in Castor, we went to a nature reserve to search for some grass snakes, adders and slow worms underneath the mats. We were quite successful and managed to capture some great pictures, for example, the picture on the right of the adder that we met.

On Tuesday morning, our task was to clear the lining of a pond at the allotment – we cleared the water from the bottom of the pond and helped to shovel some soil away from the liner and onto the bank of the pond.

In the afternoon, we were still working on the pond liner but after clearing the liner underneath, we had to lay a felt underlay over the previous liner and then a new liner on top of the underlay. After this, we needed to cover the liner with a felt overlay. The felt had to be rolled out in the opposite direction to the underlay to ensure that the liner has enough support to hold the pressure of the water when the pond is completed and full.

To complete the pond lining process, the overlay had to be covered with the soil that we had removed that morning and water to weigh it down. Due to the fact that the working day was coming to an end, it was important that we made sure that all of the excess liner was weighed down – we rolled it up and placed tyres on it.

Wednesday began with a trip to Boardwalks. We practiced geocaching – we hid eight objects around a specific route and punched the coordinates into the GPS. Next, we had to walk round the same route but this time we used the GPS to track down the objects that were hidden. I found this quite fun because I’d not used a GPS before then.

The next activity at Boardwalks was recording the frequency of certain types of butterflies we could see as we walked around six different routes. This was interesting too because I learnt the names of lots of different types of butterflies and learnt how to identify them when their wings are open and closed. The most common butterflies were the Meadow Brown and Gatekeeper butterflies, however we also came across a few Small Skippers and Red Admirals as well as Small Whites.

Later on, we visited the Green Backyard where we did some pond dipping. In the pond, we found a small newt and several different dragonfly nymphs. We also came across a big frog that was unfortunately too quick for us to catch and have a look at.

I did research on all kinds of pond life and allotment related subjects which I then used to create a sign on why ponds are helpful in an allotment. These signs will be placed in the allotment so other users will consider making a pond in their plot. I also then went on to do, in the afternoon, some research on interesting facts about frogs, toads, lizards, snakes and newts that will be used on social media as “Did You Know?” facts.

Tuesday 11th July

I started out this day helping out with some indoor decorating. I helped to paint a wall with Stuart by painting another coat of blackboard paint and I helped to strip down the sealant which was poorly put in by the previous worker. Then I went out to B&Q to help buy a new sealant that will be used in the future. Later on in the day I went out with Gail to the Froglife allotment where Gail does a scheme of helping vulnerable and disadvantaged children by letting them interact with the environment. We made willow spirals, painted flowerpot men, cut poles for bee houses and did some watering of the plants. The children looked like they benefited greatly from this scheme and they all looked like they had fun. Gail then dropped by for a 1 to 1 meeting on the way back to the Froglife headquarters.

Wednesday 12th July

I spent all of today in the office. I corrected books by sticking over the address, as these books were published in 2011, and then I helped Marie shred some documents. In the afternoon I made a word search and a crossword for a new magazine by Froglife all about reptiles. I also made a dot to dot using publisher.

Thursday 13th July

I spent the morning out at the Nature Reserve doing a Reptile Survey. I saw lots of reptiles like Adders, Grass Snakes, slow worms and Lizards. One of the Adders, which was gravid (pregnant), lifted its head at us and hissed. We also encountered an Emperor Dragonfly on our travels. In the afternoon I put together a toad colouring book and cut out toad masks.

Friday 14th July

This morning I used my time to finish off some of the toad masks. I also spell checked the Froglife website, helped around the office and went out to check up on ponds. We went to Nene Park where we found that most of the ponds had dried up because there was not enough rain. Also in Ferry Meadows one of the waterbodies had become full of blue-green algae.

Week 2

Monday 17th July

This morning we went to Castor to clear a pond out from willow and other vegetation which was over growing. We did this for most of the day. Later on in the day we went to the Nature Reserve to have a look around. We saw lots of adders and other things:

Tuesday 18th July

All day I was helping out with a huge pond. We made it a bit bigger and we cleaned it out so it would be free from stones and mud, this was so we could start placing felt. We then covered the felt in pond liner to keep the water in. We added another layer of felt. We then put soil back in to the pond along with water.

Wednesday 19th July

Today I went to Boardwalks and The Green Backyard. At Boardwalks we made a Geocache for a party that will take place there, we also did a butterfly survey during which we saw many butterflies such as Gatekeepers and even a red admiral. There was also a pack of 10 cygnets and a baby frog and 2 kingfishers. After we finished up at Boardwalks we went to The Green Backyard. In The Green Backyard we did a spot of pond dipping. I found a baby newt, some dragonfly nymphs and many more creatures.

Thursday 20th July

Today was my last day. I made a box in the morning a and I made an instruction manual for the GPS Device that will be used for geocaching. I also made clues for the Geocache trail, they included pictures of the areas. Then I uploaded this blog onto the website along with a In the Spotlight article for the Dragon Finder Newsletter.

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